docs: improved SEO of documentation (#3117)

* docs: added description to documentation pages

* docs: added more descriptions

* docs: finished improving meta description

* docs: added searchbox structured data

* docs: added breadcrumbs structured data

* docs: added how to structured data

* docs: improved 404 page

* docs: added how-to frontmatter option

docs/content/advanced/backend/payment/how-to-create-payment-provider.md

@@ -1,3 +1,8 @@
+---
+description: 'Learn how to create a payment provider in the Medusa server. This guide explains the different methods available in a fulfillment provider.'
+addHowToData: true
+---
+
 # How to Create a Payment Provider
 
 In this document, you’ll learn how to add a Payment Provider to your Medusa server. If you’re unfamiliar with the Payment architecture in Medusa, make sure to check out the [overview](./overview.md) first.

docs/content/advanced/backend/payment/overview.md

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+---
+description: 'Learn about the payment architecture in the Medusa server. The payment architecture refers to all operations in the ecommerce store related to processing payments.'
+---
+
 # Payment Architecture Overview
 
 In this document, you’ll learn about the payment architecture in Medusa, specifically its 3 main components and the idempotency key.